title: Chloroplastic and cytoplasmic valyl- and leucyl-tRNA synthetases from Euglena gracilis. Comparative study of their structural properties.
abstract: Chloroplastic and cytoplasmic valyl- and leucyl-tRNA synthetases purified from Euglena gracilis show a monomeric structure. The molecular weights of the two valyl-tRNA synthetases are identical (126,000) while those of the leucyl-tRNA synthetases are different (100 000 for the chloroplastic and 116 000 for the cytoplasmic enzyme). The tryptic maps and the amino acid compositions reveal differences between the chloroplastic valyl- and leucyl-tRNA synthetases and their cytoplasmic homologues. These results suggest that a chloroplastic aminoacyl-tRNA synthetase and its cytoplasmic counterpart are coded for by distinct genes.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification*; D000818:Animals; D002736:Chloroplasts / Q000201:enzymology*; D003593:Cytoplasm / Q000201:enzymology; D005056:Euglena gracilis / Q000201:enzymology*; D005796:Genes; D007935:Leucine-tRNA Ligase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D014637:Valine-tRNA Ligase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D000604:Amino Acyl-tRNA Synthetases; D007935:Leucine-tRNA Ligase; D014637:Valine-tRNA Ligase